Project Summary Dr. Davis-Fobian's long-term goal is to become an independent, patient-oriented investigator with a focus on implementing and evaluating interventions to address childhood and adolescent obesity and prevent type 2 diabetes. Protected time provided by successful completion of this K23 career development award will provide the foundational support necessary for achievement of this goal. The long-term objective of this research is to establish an effective intervention incorporating sleep to improve adolescent health and reduce obesity and risk for the development of type 2 diabetes. Dr. Davis-Fobian is an Assistant Professor in the Department of Psychiatry at the University of Alabama at Birmingham (UAB). Her position allows her to interact with distinguished researchers on a daily basis and provides her with the opportunity to utilize the most innovative technology. Dr. Davis-Fobian is an experienced clinical psychologist who has extensive experience in treating obese adolescents with or at risk for type 2 diabetes. It was through these clinical experiences that Dr. Davis-Fobian realized the need for new approaches to obesity treatments and developed her hypothesis that improving sleep may assist in adolescent weight loss and prevention of type 2 diabetes. The foundation of Dr. Davis-Fobian's successful career development is the distinguished mentoring team she has developed for her project, consisting of Drs. Barbara Gower, David Allison and Karen Gamble and her scientific advisory panel. Their expertise complements all areas in which Dr. Davis-Fobian would benefit from additional training. These mentors are all faculty at UAB and have a strong history of research collaborations. Career development planned for this award includes 1) training in insulin sensitivity, beta-cell function, chronobiology, biostatistical and clinical trials research and research ethics; 2) laboratory training in metabolism, body composition, and chronobiology; and 3) professional skills training. These skills will be fostered through coursework, short courses, didactic opportunities and hands-on experiences, allowing Dr. Davis-Fobian to ultimately become a nationally recognized obesity and type 2 diabetes prevention researcher. The purpose of the proposed study is to assess the effects of a sleep and media use intervention on body composition and risk for type 2 diabetes in obese adolescents aged 15-17. This will be accomplished through 2 specific aims: 1) Conduct a two-arm parallel group randomized controlled trial of the relative effects of an intervention for adolescent sleep duration and media use on sleep duration and quality, insulin sensitivity, appetite-regulating hormones, and body composition; and 2) Evaluate whether the sleep intervention affects adolescents' nighttime media use at both the end of the intervention and the 3-month follow-up.